Cover image for Vol. 18 Issue 6

Edited By: Michael S. Marks, Trina A. Schroer, Robert G. Parton and Sharon A. Tooze

Online ISSN: 1600-0854

Virtual Issue Lysosomes


Virtual Issue LysosomesVirtual issue cover legend: Melanosomal resident protein Tyrp1 labeled in green, the late endosome/lysosomal resident protein LAMP1 labeled in red, and the early sortiong/ recycling endosomal tSNARE Syntaxin 13 labeled in blue. As shown in the image, none of the markers overlap - indicating that melanosomes are distinct from early and late endosomes/ lysosomes. Image courtesy of Mickey Marks and Subba rao Gangi Setty.

Lysosomal membrane proteins and their central role in physiology

M Schwake, B Schröder and P Saftig

The BEACH is hot: A LYST of emerging roles for BEACH-domain containing proteins in human disease
AR Cullinane, AA Schäffer and M Huizing

Antagonistic Control of Lysosomal Fusion by Rab14 and the Lyst-Related Protein LvsB

Elena Kypri, Kristin Falkenstein and Arturo De Lozanne

Rab7 and Arl8 GTPases are Necessary for Lysosome Tubulation in Macrophages
Amra Mrakovic, Jason G. Kay, Wendy Furuya, John H. Brumell, Roberto J. Botelho
Traffic, Early View, Abstract
Lysosomes provide a niche for molecular digestion and are a convergence point for endocytic trafficking, phagosome maturation and autophagy. Typically, lysosomes are small, globular organelles that appear punctate under the fluorescence microscope. However, activating agents like phorbol esters transform macrophage lysosomes into tubular lysosomes (TLs), which have been implicated in retention of pinocytic uptake and phagosome maturation. Moreover, dendritic cells exposed to lipopolysaccharides (LPSs) convert their punctate class II major histocompatibility complex compartment, a lysosome-related organelle, into a tubular network that is thought to be involved in antigen presentation...

Shedding-Generated Met Receptor Fragments can be Routed to Either the Proteasomal or the Lysosomal Degradation Pathway
Frédéric Ancot, Catherine Leroy, Ghaffar Muharram, Jonathan Lefebvre, Jérôme Vicogne, Arnaud Lemiere, Zoulika Kherrouche, Bénédicte Foveau, Albin Pourtier, Oleg Melnyk, Silvia Giordano, Anne Chotteau-Lelievre, David Tulasne
Traffic, Volume 13, Issue 9:1261–1272, Abstract
The receptor tyrosine kinase Met and its ligand, the hepatocyte growth factor/scatter factor, are essential for embryonic development, whereas deregulation of Met signaling pathways is associated with tumorigenesis and metastasis. The presenilin-regulated intramembrane proteolysis (PS-RIP) is involved in ligand-independent downregulation of Met. This proteolytic process involves shedding of the Met extracellular domain followed by γ-secretase cleavage, generating labile intracellular fragments degraded by the proteasome. We demonstrate here that...

The BLOS1-Interacting Protein KXD1 is Involved in the Biogenesis of Lysosome-Related Organelles
Qing Yang, Xin He, Lin Yang, Zhiyong Zhou, Andrew R. Cullinane, Aihua Wei, Zhe Zhang, Zhenhua Hao, Aili Zhang, Min He, Yaqin Feng, Xiang Gao, William A. Gahl, Marjan Huizing and Wei Li
Traffic, Volume 13, Issue 8: 1160–1169, Abstract
Biogenesis of lysosome-related organelles (LROs) complex-1 (BLOC-1) is an eight-subunit complex involved in lysosomal trafficking. Interacting proteins of these subunits expand the understanding of its biological functions. With the implementation of the naïve Bayesian analysis, we found that a human uncharacterized 20 kDa coiled-coil KxDL protein, KXD1, is a BLOS1-interacting protein. In vitro binding assays confirmed the interaction between BLOS1 and KXD1...

Myosin VI Regulates Actin Dynamics and Melanosome Biogenesis
Sylvain Loubéry, Cédric Delevoye, Daniel Louvard, Graça Raposo and Evelyne Coudrier
Traffic, Volume 13, Issue 5: 665–680, Abstract
Myosin VI has been implicated in various steps of organelle dynamics. However, the molecular mechanism by which this myosin contributes to membrane traffic is poorly understood. Here, we report that myosin VI is associated with a lysosome-related organelle, the melanosome. Using an actin-based motility assay and video microscopy, we observed that myosin VI does not contribute to melanosome ...

Role of Protein Kinase D in Golgi Exit and Lysosomal Targeting of the Transmembrane Protein, Mcoln1
David L. Marks, Eileen L. Holicky, Christine L. Wheatley, Ayala Frumkin, Gideon Bach and Richard E. Pagano
Traffic, Volume 13, Issue 4: 565–575, Abstract
The targeting of lysosomal transmembrane (TM) proteins from theGolgiapparatus to lysosomes is a complex process that is only beginning to be understood. Here, the lysosomal targeting of mucolipin-1 (Mcoln1), theTMprotein defective in the autosomal recessive disease, mucolipidosis typeIV, was studied by overexpressing full-length and truncated forms of the protein in human cells, followed by ...

The Enlarged Lysosomes in beigej Cells Result From Decreased Lysosome Fission and Not Increased Lysosome Fusion
Nina Durchfort, Shane Verhoef, Michael B. Vaughn, Rishna Shrestha, Dieter Adam, Jerry Kaplan and Diane McVey Ward
Traffic, Volume 13, Issue 1: 108–119, Abstract
Chediak–Higashi syndrome is an autosomal recessive disorder that affects vesicle morphology. The Chs1/Lyst protein is a member of the BEige And CHediak family of proteins. The absence of Chs1/Lyst gives rise to enlarged lysosomes. Lysosome size is regulated by a balance between vesicle fusion and fission and can be reversibly altered by acidifying the cytoplasm using Acetate Ringer's or by ...

A Weak Base-Generating System Suitable for Selective Manipulation of Lysosomal pH
Luciene R. Carraro-Lacroix, Valentin Jaumouillé, Gregory D. Fairn and Sergio Grinstein
Traffic, Volume 12, Issue 11: 1490–1500, Abstract
pH varies widely among the different intracellular compartments. The establishment and maintenance of a particular pH appears to be critical for proper organellar function. This has been deduced from experiments where intraorganellar pH was altered by means of weak acids or bases, ionophores or inhibitors of the vacuolar H+-ATPase (V-ATPase). These manipulations, however, are not ...

Hyperacidification of Trans-Golgi Network and Endo/Lysosomes in Melanocytes by Glucosylceramide-Dependent V-ATPase Activity
Seléne van der Poel, Jasja Wolthoorn, Dave van den Heuvel, Maarten Egmond, Sophie Groux-Degroote, Sylvia Neumann, Hans Gerritsen, Gerrit van Meer and Hein Sprong
Traffic, Volume 12, Issue 11: 1634–1647, Abstract
Sphingolipids are considered to play a key role in protein sorting and membrane trafficking. In melanocytic cells, sorting of lysosomal and melanosomal proteins requires the sphingolipid glucosylceramide (GlcCer). This sorting information is located in the lumenal domain of melanosomal proteins. We found that two processes dependent on lumenal pH, protein sialylation and lysosomal acid ...

The Role of VAMP7/TI-VAMP in Cell Polarity and Lysosomal Exocytosis in vivo
Mahito Sato, Shinichiro Yoshimura, Rika Hirai, Ayako Goto, Masataka Kunii, Nur Atik, Takashi Sato, Ken Sato, Reiko Harada, Junko Shimada, Toshimitsu Hatabu, Hiroshi Yorifuji and Akihiro Harada
Traffic, Volume 12, Issue 10: 1383–1393, Abstract
VAMP7 or tetanus neurotoxin-insensitive vesicle- associated membrane protein (TI-VAMP) has been proposed to regulate apical transport in polarized epithelial cells, axonal transport in neurons and lysosomal exocytosis. To investigate the function of VAMP7 in vivo, we generated VAMP7 knockout mice. Here, we show that VAMP7 knockout mice are indistinguishable from control mice and ...

The Polymorphic HCMV Glycoprotein UL20 Is Targeted for Lysosomal Degradation by Multiple Cytoplasmic Dileucine Motifs
Ivan Jelcic, Johanna Reichel, Christoph Schlude, Eva Treutler, Christian Sinzger and Alexander Steinle
Traffic, Volume 12, Issue 10: 1444–1456, Abstract
Human cytomegalovirus (HCMV) is a widespread and persistent beta-herpesvirus. The large DNA genome of HCMV encodes many proteins that are non-essential for viral replication including numerous proteins subverting host immunosurveillance. One of them is the barely characterized UL20, which is encoded adjacent to the well-defined immunoevasins UL16 and UL18. UL20 is a type I ...

Lysosomal Membrane Protein Composition, Acidic pH and Sterol Content are Regulated via a Light-Dependent Pathway in Metazoan Cells
. G. Swetha, V. Sriram, K. S. Krishnan, Viola M. J. Oorschot, Corlinda ten Brink, Judith Klumperman and Satyajit Mayor
Traffic, Volume 12, Issue 8: 1037–1055, Abstract
In metazoans, lysosomes are characterized by a unique tubular morphology, acidic pH, and specific membrane protein (LAMP) and lipid (cholesterol) composition as well as a soluble protein (hydrolases) composition. Here we show that perturbation to the eye-color gene, light, results in impaired lysosomal acidification, sterol accumulation, altered endosomal morphology as well as compromised lysosomal ...

Rab27a Targeting to Melanosomes Requires Nucleotide Exchange but Not Effector Binding
Abul K. Tarafder, Christina Wasmeier, Ana C. Figueiredo, Antonia E. G. Booth, Asumi Orihara, Jose S. Ramalho, Alistair N. Hume and Miguel C. Seabra
Traffic, Volume 12, Issue 8: 1056–1066, Abstract
Rab GTPases are important determinants of organelle identity and regulators of vesicular transport pathways. Consequently, each Rab occupies a highly specific subcellular localization. However, the precise mechanisms governing Rab targeting remain unclear. Guanine nucleotide exchange factors (GEFs), putative membrane-resident targeting factors and effector binding have all been implicated as critical ...

Disruption of the Man-6-P Targeting Pathway in Mice Impairs Osteoclast Secretory Lysosome Biogenesis
Eline van Meel, Marielle Boonen, Haibo Zhao, Viola Oorschot, F. Patrick Ross, Stuart Kornfeld and Judith Klumperman
Traffic, Volume 12, Issue 7: 912–924, Abstract
Osteoclasts are specialized cells that secrete lysosomal acid hydrolases at the site of bone resorption, a process critical for skeletal formation and remodeling. However, the cellular mechanism underlying this secretion and the organization of the endo-lysosomal system of osteoclasts have remained unclear. We report that osteoclasts differentiated in vitro from murine bone marrow ...

Peroxisome Fission is Associated with Reorganization of Specific Membrane Proteins
Małgorzata N. Cepińska, Marten Veenhuis, Ida J. van der Klei and Shirisha Nagotu
Traffic, Volume 12, Issue 7: 925–937, Abstract
Membrane remodeling is an important aspect in organelle biogenesis. We show that different peroxisome membrane proteins that play a role in organelle biogenesis and proliferation (Pex8, Pex10, Pex14, Pex25 and Pex11) are subject to spatiotemporal behavior during organelle development. Using fluorescence microscopy analysis of Hansenula polymorpha dnm1 cells that are blocked in the ...

Syntaxin 11 Binds Vti1b and Regulates Late Endosome to Lysosome Fusion in Macrophages
Carolin Offenhäuser, Nazi Lei, Sandrine Roy, Brett M. Collins, Jennifer L. Stow and Rachael Z. Murray
Traffic, Volume 12, Issue 6: 762–773, Abstract
Syntaxin 11 (Stx11) is a SNARE protein enriched in cells of the immune system. Loss or mutation of Stx11 results in familial hemophagocytic lymphohistiocytosis type-4 (FHL-4), an autosomal recessive disorder of immune dysregulation characterized by high levels of inflammatory cytokines along with defects in T-cell and natural killer cell function. We show here Stx11 is located on ...

The Role of Ubiquitination in Lysosomal Trafficking of δ-Opioid Receptors
Anastasia G. Henry, Ian J. White, Mark Marsh, Mark von Zastrow and James N. Hislop
Traffic, Volume 12, Issue 2: 170–184, Abstract
The δ-opioid receptor (DOR) undergoes ligand-induced downregulation by endosomal sorting complex required for transport (ESCRT)-dependent endocytic trafficking to lysosomes. In contrast to a number of other signaling receptors, the DOR can downregulate effectively when its ubiquitination is prevented. We explored the membrane trafficking basis of this behavior. First, we ...

Type I Cannabinoid Receptor Trafficking: All Roads Lead to Lysosome
Raphael Rozenfeld
Traffic, Volume 12, Issue 1: 12–18, Abstract
The majority of G-protein-coupled receptors (GPCRs) function at the cell surface, where they are activated by their ligands present in the extracellular milieu. Interestingly, type I cannabinoid receptor (CB1R), one of the most abundant GPCRs in the central nervous system, is predominantly intracellular. The important physiological roles of CB1R have sparked interest in the elucidation of the ...

Lysosomal Targeting of the CLN7 Membrane Glycoprotein and Transport Via the Plasma Membrane Require a Dileucine Motif
Pieter Steenhuis, Stephanie Herder, Suyin Gelis, Thomas Braulke, Stephan Storch
Traffic, Volume 11 Issue 7: 987 - 1000, Abstract
CLN7 is a polytopic lysosomal membrane protein deficient in variant late infantile neuronal ceroid lipofuscinosis, a neurodegenerative lysosomal storage disorder. In this study fluorescence protease protection assays and mutational analyses revealed the N- and C-terminal tails of CLN7 in the cytosol and two N-glycosylation sites at N371 and N376. Both partially and non-glycosylated ...

Early Origin of Genes Encoding Subunits of Biogenesis of Lysosome-related Organelles Complex-1, -2 and -3
Verónica T. Cheli, Esteban C. Dell'Angelica
Traffic, Volume 11 Issue 5: 579 - 586, Abstract
Biogenesis of lysosome-related organelles complex (BLOC)-1, -2 and -3 are three multi-subunit protein complexes that are deficient in various forms of Hermansky-Pudlak syndrome, a human disease characterized by abnormal formation of lysosome-related organelles. Contrasting views have arisen on the evolutionary origin of these protein complexes. One view is that the BLOCs represent a recent evolutionary 'acquisition' unique to metazoans. However, the yeast proteins Mon1, Ccz1 ...

Rab10 Regulates Phagosome Maturation and Its Overexpression Rescues Mycobacterium-Containing Phagosomes Maturation
Carla M. P. Cardoso, Luisa Jordao, Otilia V. Vieira
Traffic, Volume 11 Issue 2: 221 - 235, Abstract
Phagosome maturation follows a defined biochemical program and, in the vast majority of cases, the microbe inside the phagosome is killed and digested. Although, an important number of pathogens, including Mycobacterium tuberculosis, which kills around two million people every year, have acquired the ability to survive, and even replicate by arresting phagosomal maturation. ...

Thiazolidinediones Induce Rab7–RILP–MAPK-Dependent Juxtanuclear Lysosome Aggregation and Reduce Tumor Cell Invasion
Joshua J. Steffan, James A. Cardelli
Traffic, Volume 11 Issue 2: 274 - 286, Abstract
Acidic extracellular pH (pHe) has been shown to stimulate peripheral lysosome trafficking, resulting in cathepsin B secretion and tumor invasion. In addition, inhibitors of sodium-proton exchangers (NHE) such as EIPA, cariporide and s3226, as well as the non-specific NHE inhibitor, troglitazone (Tro), blocked these changes. In this paper, we report a differential ability of the ...

Peroxisome Dynamics in Cultured Mammalian Cells
Sofie J. Huybrechts, Paul P. Van Veldhoven, Chantal Brees, Guy P. Mannaerts, Georgyi V. Los, Marc Fransen
Traffic, Volume 10 Issue 11: 1722 - 1733, Abstract
Despite the identification and characterization of various proteins that are essential for peroxisome biogenesis, the origin and the turnover of peroxisomes are still unresolved critical issues. In this study, we used the HaloTag technology as a new approach to examine peroxisome dynamics in cultured mammalian cells. This technology is based on the formation of a covalent bond ...

A Helical Membrane-Binding Domain Targets the Toxoplasma ROP2 Family to the Parasitophorous Vacuole
Michael L. Reese, John C. Boothroyd
Traffic, Volume 10 Issue 10: 1458 - 1470, Abstract
During invasion, the obligate intracellular pathogen, Toxoplasma gondii, secretes into its host cell a variety of effector molecules, several of which have been implicated in strain-specific variation in disease. The largest family of these effectors, defined by the canonical member ROP2, quickly associates with the nascent parasitophorous vacuole membrane (PVM) after secretion. Here we ...

Membrane Contact Sites between Apicoplast and ER in Toxoplasma gondii Revealed by Electron Tomography
Cveta Tomova, Bruno M. Humbel, Willie J. C. Geerts, Rolf Entzeroth, Joost C. M. Holthuis, Arie J. Verkleij
Traffic, Volume 10 Issue 10: 1471 - 1480, Abstract
Toxoplasma gondii is an obligate intracellular parasite from the phylum Apicomplexa. A hallmark of these protozoans is the presence of a unique apical complex of organelles that includes the apicoplast, a plastid acquired by secondary endosymbiosis. The apicoplast is indispensible for parasite viability. It harbours a fatty acid biosynthesis type II (FAS II) pathway and plays a key role in ...

MHC II in Dendritic Cells is Targeted to Lysosomes or T Cell-Induced Exosomes Via Distinct Multivesicular Body Pathways
Sonja I. Buschow, Esther N. M. Nolte-'t Hoen, Guillaume van Niel, Maaike S. Pols, Toine ten Broeke, Marjolein Lauwen, Ferry Ossendorp, Cornelis J. M. Melief, Graça Raposo, Richard Wubbolts, Marca H. M. Wauben, Willem Stoorvogel
Traffic, Volume 10 Issue 10: 1528 - 1542, Abstract
Dendritic cells (DCs) express major histocompatibility complex class II (MHC II) to present peptide antigens to T cells. In immature DCs, which bear low cell surface levels of MHC II, peptide-loaded MHC II is ubiquitinated. Ubiquitination drives the endocytosis and sorting of MHC II to the luminal vesicles of multivesicular bodies (MVBs) for lysosomal degradation. Ubiquitination of MHC II is ...

ESCRT-I Function is Required for Tyrp1 Transport from Early Endosomes to the Melanosome Limiting Membrane
Steven T. Truschel, Sabrina Simoes, Subba Rao Gangi Setty, Dawn C. Harper, Danièle Tenza, Penelope C. Thomas, Kathryn E. Herman, Sara D. Sackett, David C. Cowan, Alexander C. Theos, Graça Raposo, Michael S. Marks
Traffic, Volume 10 Issue 9: 1318 - 1336, Abstract
Melanosomes are lysosome-related organelles that coexist with lysosomes within melanocytes. The pathways by which melanosomal proteins are diverted from endocytic organelles toward melanosomes are incompletely defined. In melanocytes from mouse models of Hermansky-Pudlak syndrome that lack BLOC-1, melanosomal proteins such as tyrosinase-related protein 1 ...

Nudel Promotes Axonal Lysosome Clearance and Endo-lysosome Formation via Dynein-Mediated Transport
Qiangge Zhang, Fubin Wang, Jingli Cao, Yidong Shen, Qiongping Huang, Lan Bao, Xueliang Zhu
Traffic, Volume 10 Issue 9: 1337 - 1349, Abstract
Axonal transport is critical for neuronal function and survival. Cytoplasmic dynein and its accessory complex dynactin form a microtubule minus end-directed motor in charge of retrograde transport. In this study, we show that Nudel, a dynein regulator, was highly expressed in dorsal root ganglion (DRG) neurons. Microinjection of anti-Nudel antibody into cultured DRG neurons ...

Involvement of Vps33a in the Fusion of Uroplakin-Degrading Multivesicular Bodies with Lysosomes
Xuemei Guo, Liyu Tu, Iwona Gumper, Heide Plesken, Edward K. Novak, Sreenivasulu Chintala, Richard T. Swank, Gregory Pastores, Paola Torres, Tetsuro Izumi, Tung-Tien Sun, David D. Sabatini, Gert Kreibich
Traffic, Volume 10 Issue 9: 1350 - 1361, Abstract
The apical surface of the terminally differentiated mouse bladder urothelium is largely covered by urothelial plaques, consisting of hexagonally packed 16-nm uroplakin particles. These plaques are delivered to the cell surface by fusiform vesicles (FVs) that are the most abundant cytoplasmic organelles. We have analyzed the functional involvement of several proteins in the apical ...

Site-Specific Ubiquitination Determines Lysosomal Sorting and Signal Attenuation of the Granulocyte Colony-Stimulating Factor Receptor
Albert Wölfler, Mahban Irandoust, Annemarie Meenhuis, Judith Gits, Onno Roovers, Ivo P. Touw
Traffic, Volume 10 Issue 8: 1168 - 1179, Abstract
Ubiquitination of cytokine receptors controls intracellular receptor routing and signal duration, but the underlying molecular determinants are unclear. The suppressor of cytokine signaling protein SOCS3 drives lysosomal degradation of the granulocyte colony-stimulating factor receptor (G-CSFR), depending on SOCS3-mediated ubiquitination of a specific lysine located in a ...

Two Fission Yeast Rab7 Homologs, Ypt7 and Ypt71, Play Antagonistic Roles in the Regulation of Vacuolar Morphology
Jun Kashiwazaki, Tomoko Iwaki, Kaoru Takegawa, Chikashi Shimoda, Taro Nakamura
Traffic, Volume 10 Issue 7: 912 - 924, Abstract
Small guanine triphosphatases (GTPases) of the Rab family are key regulators of membrane trafficking events between the various subcellular compartments in eukaryotic cells. Rab7 is a conserved protein required in the late endocytic pathway and in lysosome biogenesis. A Schizosaccharomyces pombe (S. pombe) homolog of Rab7, Ypt7, is necessary for trafficking from the ...

Multivesicular Endosome Biogenesis in the Absence of ESCRTs
Susanne Stuffers, Catherine Sem Wegner, Harald Stenmark, Andreas Brech
Traffic, Volume 10 Issue 7: 925 - 937, Abstract
The endosomal sorting complex required for transport (ESCRT) protein machinery comprises four complexes, ESCRT-0, ESCRT-I, ESCRT-II and ESCRT-III, that facilitate receptor sorting into the lumen of multivesicular endosomes (MVEs) in order to terminate signalling receptors for final degradation within the lysosomes. Even though ESCRT proteins appear to be essential for the ...

Peroxisomal Targeting of PTS2 Pre-Import Complexes in the Yeast Saccharomyces cerevisiae
Silke Grunau, Wolfgang Schliebs, Ruth Linnepe, Christian Neufeld, Christian Cizmowski, Benedikt Reinartz, Helmut E. Meyer, Bettina Warscheid, Wolfgang Girzalsky, Ralf Erdmann
Traffic, Volume 10 Issue 4: 451 - 460, Abstract
Posttranslational matrix protein import into peroxisomes uses either one of the two peroxisomal targeting signals (PTS), PTS1 and PTS2. Unlike the PTS1 receptor Pex5p, the PTS2 receptor Pex7p is necessary but not sufficient to target cargo proteins into the peroxisomal matrix and requires coreceptors. Saccharomyces cerevisiae possesses two coreceptors, Pex18p and ...

The Protein Kinase A-Anchoring Protein Moesin is Bound to Pigment Granules in Melanophores
Irina Semenova, Kazuho Ikeda, Pavel Ivanov, Vladimir Rodionov
Traffic, Volume 10 Issue 2: 153 - 160, Abstract
Major signaling cascades have been shown to play a role in the regulation of intracellular transport of organelles. In Xenopus melanophores, aggregation and dispersion of pigment granules are regulated by the second messenger cyclic AMP through the protein kinase A (PKA) signaling pathway. PKA is bound to pigment granules where it forms complexes with molecular motors ...

Dictyostelium Tom1 Participates to an Ancestral ESCRT-0 Complex
Cédric Blanc, Steve J. Charette, Sara Mattei, Laurence Aubry, Ewan W. Smith, Pierre Cosson, François Letourneur
Traffic, Volume 10 Issue 2: 161 - 171, Abstract
Sorting of ubiquitinated proteins to multivesicular bodies (MVBs) in mammalian cells relies on proteins with a Vps27/Hrs/STAM (VHS) domain. Here, we show that the amoeba Dictyostelium presents only one protein with a VHS domain: DdTom1. We demonstrate that the VHS domain of DdTom1 is followed by a Golgi-localized, ?-ear-containing, ADP-ribosylation-factor-binding and ...

The C. elegans P4-ATPase TAT-1 Regulates Lysosome Biogenesis and Endocytosis
Anne-Françoise Ruaud, Lars Nilsson, Fabrice Richard, Morten Krog Larsen, Jean-Louis Bessereau, Simon Tuck
Traffic, Volume 10 Issue 1: 88 - 100, Abstract
P-type adenosine triphosphatases (ATPases) of the Drs2p family (P4-ATPases) are multipass transmembrane proteins required to generate and maintain phospholipid asymmetry in membrane bilayers. In Saccharomyces cerevisiae, several members of this family control distinct transport events within the endosomal and secretory pathways. Comparatively, little is known about the ...

Salmonella-Containing Vacuoles: Directing Traffic and Nesting to Grow
Malina A. Bakowski, Virginie Braun, John H. Brumell
Traffic, Volume 9 Issue 12: 2022 - 2031, Abstract
Salmonella enterica serovar Typhimurium (S. typhimurium) is a gram-negative facultative intracellular pathogen that can infect a broad range of mammalian hosts. Following invasion of host cells, the majority of S. typhimurium are known to reside in a membrane-bound compartment known as the Salmonella-containing vacuole (SCV). S. typhimurium actively remodels this ...

Infectious Adenovirus Type 2 Transport Through Early but not Late Endosomes
Michele Gastaldelli, Nicola Imelli, Karin Boucke, Beat Amstutz, Oliver Meier, Urs F. Greber
Traffic, Volume 9 Issue 12: 2265 - 2278, Abstract
Receptor-mediated endocytosis is a major gate for pathogens into cells. In this study, we analyzed the trafficking of human adenovirus type 2 and 5 (Ad2/5) and the escape-defective temperature-sensitive Ad2-ts1 mutant in epithelial cancer cells. Ad2/5 and Ad2-ts1 uptake into endosomes containing transferrin, major histocompatibility antigen 1 and the Rab5 effector early endosome ...

The ESCRT-I Subunit TSG101 Controls Endosome-to-Cytosol Release of Viral RNA
Pierre-Philippe Luyet, Thomas Falguières, Véronique Pons, Asit K. Pattnaik, Jean Gruenberg
Traffic, Volume 9 Issue 12: 2279 - 2290, Abstract
Like other enveloped viruses, vesicular stomatitis virus infects cells through endosomes. There, the viral envelope undergoes fusion with endosomal membranes, thereby releasing the nucleocapsid into the cytoplasm and allowing infection to proceed. Previously, we reported that the viral envelope fuses preferentially with the membrane of vesicles present within multivesicular endosomes ...

Palmitoylation Controls Recycling in Lysosomal Sorting and Trafficking
Peter J. McCormick, Karine Dumaresq-Doiron, Anne-Sophie Pluviose, Vincent Pichette, Giovanna Tosato, Stephane Lefrancois
Traffic, Volume 9 Issue 11: 1984 - 1997, Abstract
For the efficient trafficking of lysosomal proteins, the cationic-dependent and -independent mannose 6-phosphate receptors and sortilin must bind cargo in the Golgi apparatus, be packaged into clathrin-coated trafficking vesicles and traffic to the endosomes. Once in the endosomes, the receptors release their cargo into the endosomal lumen and recycle back to the Golgi for another ...

The Peroxisome RING-Finger Complex is Required for Meiocyte Formation in the Fungus Podospora anserina
Leonardo Peraza-Reyes, Denise Zickler, Véronique Berteaux-Lecellier
Traffic, Volume 9 Issue 11: 1998 - 2009, Abstract
Peroxisomes are involved in a variety of metabolic pathways and developmental processes. In the filamentous fungus Podospora anserina, absence of different peroxins implicated in peroxisome matrix protein import leads to different developmental defects. Lack of the RING-finger complex peroxin PEX2 blocks sexual development at the dikaryotic stage, while in absence of ...

Evolution of the Multivesicular Body ESCRT Machinery; Retention Across the Eukaryotic Lineage
Ka Fai Leung, Joel B. Dacks, Mark C. Field
Traffic, Volume 9 Issue 10: 1698 - 1716, Abstract
Lysosomal targeting of ubiquitylated endocytic cargo is mediated in part by the endosomal sorting complex required for transport (ESCRT) complexes, a system conserved between animals and fungi (Opisthokonta). Extensive comparative genomic analysis demonstrates that ESCRT factors are well conserved across the eukaryotic lineage and complexes I, II, III and III-associated are ...

Depalmitoylation of Ykt6 Prevents its Entry into the Multivesicular Body Pathway
Christoph T. A. Meiringer, Kathrin Auffarth, Haitong Hou, Christian Ungermann
Traffic, Volume 9 Issue 9: 1510 - 1521, Abstract
The dually lipidated SNARE Ykt6 is found on intracellular membranes and in the cytosol. In this study, we show that Ykt6 localizes to the Golgi as well as endosomal and vacuolar membranes in vivo. The ability of Ykt6 to cycle between the cytosol and the membranes depends on the intramolecular interaction of the N-terminal longin and C-terminal SNARE domains and not on either ...

TrkA Receptor Endolysosomal Degradation is Both Ubiquitin and Proteasome Dependent
Thangiah Geetha, Marie W. Wooten
Traffic, Volume 9 Issue 7: 1146 - 1156, Abstract
Gaps in our knowledge exist regarding the degradation of the tropomyosin-regulated kinase A (TrkA) receptor after addition of neurotrophin, nerve growth factor (NGF). TrkA is rapidly and transiently ubiquitinated upon addition of NGF. Here, we demonstrate that the polyubiquitin tag plays a definitive role in receptor sorting. Treatment of PC12 cells with lactacystin prevented NGF- ...

AP-1 and AP-3 Mediate Sorting of Melanosomal and Lysosomal Membrane Proteins into Distinct Post-Golgi Trafficking Pathways
Björn Chapuy, Ritva Tikkanen, Chris Mühlhausen, Dirk Wenzel, Kurt von Figura, Stefan Höning
Traffic, Volume 9 Issue 7: 1157 - 1172, Abstract
The adaptor complexes AP-1 and AP-3 are localized to endosomes and/or the trans Golgi network (TGN). Because of limitations in analysing intracellular adaptor function directly, their site of function is a matter of ongoing uncertainty. To overcome this problem and to analyse adaptor sorting at the TGN, we reconstituted vesicle formation from Golgi/TGN-enriched membranes in a ...

Glycolipid-Dependent Sorting of Melanosomal from Lysosomal Membrane Proteins by Lumenal Determinants
Sophie Groux-Degroote, Suzanne M. van Dijk, Jasja Wolthoorn, Sylvia Neumann, Alexander C. Theos, Ann M. De Mazière, Judith Klumperman, Gerrit van Meer, Hein Sprong
Traffic, Volume 9 Issue 6: 951 - 963, Abstract
Melanosomes are lysosome-related organelles that coexist with lysosomes in mammalian pigment cells. Melanosomal and lysosomal membrane proteins share similar sorting signals in their cytoplasmic tail, raising the question how they are segregated. We show that in control melanocytes, the melanosomal enzymes tyrosinase-related protein 1 (Tyrp1) and tyrosinase follow an ...

Brucella Intracellular Replication Requires Trafficking Through the Late Endosomal/Lysosomal Compartment
Tregei Starr, Tony W. Ng, Tara D. Wehrly, Leigh A. Knodler, Jean Celli
Traffic, Volume 9 Issue 5: 678 - 694, Abstract
Upon entry into mammalian cells, the intracellular pathogen Brucella abortus resides within a membrane-bound compartment, the Brucella-containing vacuole (BCV), the maturation of which is controlled by the bacterium to generate a replicative organelle derived from the endoplasmic reticulum (ER). Prior to reaching the ER, Brucella is believed to ensure its intracellular survival by ...

The Itinerary of Autophagosomes: From Peripheral Formation to Kiss-and-Run Fusion with Lysosomes
Luca Jahreiss, Fiona M. Menzies, David C. Rubinsztein
Traffic, Volume 9 Issue 4: 574 - 587, Abstract
Macroautophagy, a constitutive process in higher eukaryotic cells, mediates degradation of many long-lived proteins and organelles. The actual events occurring during the process in the dynamic system of a living cell have never been thoroughly investigated. We aimed to develop a live-cell assay in which to follow the complete itinerary of an autophagosome. Our experiments ...

Altered Composition and Secretion of Lysosome-Derived Compartments in Dictyostelium AP-3 Mutant Cells
Steve J. Charette, Pierre Cosson
Traffic, Volume 9 Issue 4: 588 - 596, Abstract
Genetic alteration of the adaptor protein (AP)-3 complex is responsible for the type 2 Hermansky–Pudlak syndrome, a lysosomal storage disease similar to the Chediak–Higashi syndrome (CHS). AP-3 presumably participates in the biogenesis of late endosomal compartments and may also be critical for the regulated secretion of lysosomes by specialized cells. Here, Dictyostelium ...

Ligand Binding Induces Cbl-Dependent EphB1 Receptor Degradation Through the Lysosomal Pathway
Katrin Fasen, Douglas Pat Cerretti, Uyen Huynh-Do
Traffic, Volume 9 Issue 2: 251 - 266, Abstract
Eph receptor tyrosine kinases play a critical role in embryonic patterning and angiogenesis. In the adult, they are involved in carcinogenesis and pathological neovascularization. However, the mechanisms underlying their role in tumor formation and metastasis remain to be defined. Here, we demonstrated that stimulation of EphB1 with ephrinB1/Fc led to a marked downregulation of ...

Cytosol to Lysosome Transport of Intracellular Antigens During Immune Surveillance
Victoria L. Crotzer, Janice S. Blum
Traffic, Volume 9 Issue 1: 10 - 16, Abstract
The delivery of intracellular substrates such as misfolded proteins and damaged organelles from the cytosol to the lysosome for degradation is crucial for cell survival. Multiple transport pathways including bulk autophagy (microautophagy and macroautophagy) and chaperone-mediated autophagy (CMA) have been identified to efficiently facilitate this transit of macromolecules ...